Gyratory sifter



- June 5, 1934. I L. KEEPER I 1,951,669

- GYRATORY SIFTER- Filed March 11, 1931 s She'ets-Sheet 1 mm E.ZflaZierlfiger June 5, 1934.

W. L. KEEFER I GYRATORY SIFTER Filed March 11. 1931 3 Sheets-Sheet 2SWIM/om Zfla ZZerl. 6 948? Patented June 5, 1934 UNITED STATES GYRATORYSIFTER Walter L. Keefer, Chambersburg, Pa., assignor to Harry G. Wolf,Chambersburg, Pa.

Application March 11, 1931, Serial No. 521,814

1 Claim.

The invention relates to grading, sifting, screening and analogousmachines of a known type in which the screening frame or the like isgyrated by rotary power-driven means disposed vertically and having aneccentric connection with said frame, the aforesaid rotary means beingstationarily mounted upon a floor or other adequate supporting means.During its gyration, the frame creates a powerful centrifugal force,which unbalanced would produce severe vibration to the detriment of themachine and the mill or the like in which used, as well as causing greatannoyance. It is the principal object of the present invention however,to provide novel means whereby the aforementioned centrifugal force isso balanced as to prevent excessive vibration, hence becomingunobjectionable.

A further aim is to provide novel means for holding the screening frameor the like against rotation while permitting it to gyrate.

Yet another object is to provide a comparatively simple and inexpensiveconstruction, yet one which will be efficient and desirable from variousstand-points.

With the foregoing in view, the invention resides in the novel subjectmatter hereinafter described and claimed, description being accomplishedby reference to the accompanying drawings.

Fig. 1 is a side elevation of a gyratory sifter embodying myimprovements.

Fig. 2 is a top plan view'partly broken away, showing the mechanism forgyrating the screening frame or the like, the frame being omitted fromthis view.

Fig. 3 is a vertical sectional View partly in elevation as indicated byline 3 -3 of Fig. 2.

Fig. 4 is a horizontal sectional view on line li-4 of Fig. 3.

A preferred construction has been shown and will be rather specificallydescribed, with the understanding however, that within the scope of theinvention as claimed, numerous variations may be made.

The numeral 5 denotes a horizontal base frame adapted for anchorage to afloor or other support, said frame being shown as provided with feet 6for anchorage purposes. The frame 5 embodies a rigid horizontal spider'7 which supports a rigid upstanding bearing stub 8. A short verticalshaft or hub 9 is rotatably mounted upon this hearing stub 8, beingprovided substantially throughout its length with a bore 10 in whichsaid stub is received. The lower end of bore 10 is enlarged at 11 andcontains an anti-friction bearing 12 arranged to resist downward thrustas well as radial thrust. Another anti-friction bearing 13 centers theupper end of the bearing stub 8 in the bore 10.

The shaft or hub 9 is provided with a second bore 1 extendingsubstantially throughout its length and enlarged at its upper end asshown at 15. A second bearing stub 16 is rotatably received in the bore14 and is provided near its upper end with a bearing 17 similar to thebearing 12. with a bearing 18 similar to the bearing 13. The upper endof the stub 16 rigidly supports a saddle 19 for the screening frame orthe like 20.

The saddle l9 embodies an elongated horizontal plate 21 whose center isrigidly supported by the stub 16, the ends of said plate being providedwith integral vertical flanges 22 which are disposed in parallel planes.Between their ends, the flanges 22 are provided with slots or otheropenings 23 receiving bolts or other trunnions 24 projecting fromopposite sides of the frame 20, which sides are engaged by the flanges22. Near their ends, these flanges 22 are provided with vertical slots25 which receive clamping bolts 26 engaged with the frame 20. When thebolts 26 are loosened, frame 20 may be tilted to the most desiredposition or may be leveled, as may be required, and tightening of thebolts will then secure said frame to the saddle 19.

I have shown a pulley 27 on the lower end of the shaft or hub 9, saidpulley engaging a drive belt 28. This belt may be driven by an electricmotor 29 or otherwise. The additional belt 30 shown in Fig. 1 is part ofdriving means for a feeder (not shown) which feeds the material to bescreened, sifted or the like, into the inlet 31 of the screening frame20. While I have referred to this member 20 as a screening frame, it isusually of box-like form, but as my improvements are operable regardlessof the type of frame, the invention is not to be considered asrestricted to one kind of screening frame or another. Moreover, gyratorymembers for performing work other than screening, could Well besubstituted for the frame 20.

As the shaft or hub 9 is rotated, the frame 20 is gyrated and during itsgyration, said frame creates a powerful centrifugal force. Connectedwith the lower portion of the shaft or hub 9 and preferably secured tothe lower side of the pulley 27, is a weight 32 which also createscentrifugal force while the machine is in operation. The centrifugalforces generated by the frame 20 and the weight 32, are substantiallyequal and are exerted in the same direction. In a plane between theweight 32 and the frame 20 however, another weight is secured to theshaft or hub 9, said other weight creating a centrifugal force in theopposite direction from that created by the parts 20 and 32, and saidopposite centrifugal force is substantially equal to the two aforesaidforces com bined. The additional weight in question, is here shown asconsisting of one mass 33 integral with the upper end of the shaft orhub 9, and an aux- The lower end of the stub 16 is equipped iliary mass34 secured by cap screws 35 to said mass 33. The weight 32 is preferablysecured by bolts or the like 36 to the pulley 2'7, and when frames 20 ofdifferent sizes are used, or when different numbers of screens or thelike are employed within said fr mes, the weights 32 and 34 may bedetached and others substituted having the requisite mass for producingthe desiredcounterbalancing.

By providing the structure in which the frame 20 and the weight 32 exertsubstantially equal centrifugal forces in one direction, and in whichweight 33-3l or the like creates an opposite centrifugal forcesubstantially equal to the two aforesaid forces combined, a structure isproduced which is in substantially dynamic balance, so that practicallyno Vibration will take place in the operation of the m chine.

Provision is made for holding the saddle l9 and the frame 20 againstrotation, while permitting the necessary gyration, and like the gyratingand balancing means, said provision for preventing rotation, is disposedtotally beneath said frame 20. The structure described below ispreferably followed.

A forked bracket 3'? is suitably secured at 38 to the plate 21 andprojects laterally therefrom. A similar forked bracket 39 is secured bybelts or the like 4-0 to the base frame 5. Upper and lower universaljoints 41 and 42 are pivoted on horizontal axes l3 and 44 respectively,between the arrns of the upper and lower brackets 37 and 39, said join sheld against rotation by said brackets. A short vertical shaft 45extends between and is operatively connected with the universal jointsll. and i2 and is held against rotation by said joints. The shafthowever may describe a conical pendulum. Thus, while this shaft willallow the proper gyration of the saddle l9 and the frame 20, it will notallow rotation of these parts.

Preferably, a suitable housing so is mounted on the base frame 5 aroundmovable parts, said housing having openings 47 through which the belt 28passes.

By providing the novel construction shown and described, or asubstantial equivalent thereof, a machine is provided which willsmoothly operate in substantially dynamic balance and will be highlyefficient. Attention is invited to the fact that all off-center weightsfor dynamically balancing, are below the frame 20. I am aware that oneweight has heretofore been used at a similar location in an attempt todynamically balance the frame, but has proven inefficient. The weight towhich refer necessarily rotates in a plane below the plane along whichthe center of mass of the frame (corresponding to 20) travels. The twomasses consequently seek a common plane as the machine is rapidlydriven, and in so doing, they exert a tremendous leverage upon therotary frame gyrating means. In my invention however, the opposingcentrifugal force created-by the weight or the like, is in a planebetween the planes in which the frame 20 and the weight 32 exert theircentrifugal forces. Hence, the above nentioned leverage actionsubstantially disappears.

A much more desirable and durable construction than has heretofore beenprovided, is produced by using the long overlapped bearing studs 8 and16, disposed in bores extending substantially throughout the length ofthe short shaft or hub 9. While this structure is preferred, it is ofcourse to be understood that within the scope of the invention asclaimed, some other suitable rotary supporting means could be providedfor the shaft or the like 9, and that other desirable provision could bemade for establishing an eccentric connection between the upper end ofsaid part 9 and the frame 20. Similarly, while the universal joints ofthe shaft 45 are preferably employed to hold the frame 28 againstrotation, other provision could of course be made for this purpose. Theparts in question however are desirable not only because of theirsimplicity and efficiency, but because they, like all other movingparts, are totally below the frame 20, being therefore absolutely out ofthe way.

'While only one embodiment of the invention has been disclosed, it is tobe understood that it may well assume other forms. Moreover, while thedisclosed construction supports the screen ing frame 20, it will beunderstood that this frame could be supported in oti er ways. Moreover,while in the present embodiment of the invention, the same shaft whichdrives the counterbalancing weights, imparts the gyratory motion to thescreening frame, it will be understood that such motion could besupplied in other ways, utilizing the gist of the present invention onlyfor counter-balancing purposes.

I claim:

In a screen gyrating means, a horizontal base having side bars and anend bar, a horizontal spider having two arms secured to said side barsand a third arm secured to said end bar, an upstanding stub shaftrigidly carried by said spider and having a weight-sustaining rollerbearing at its lower end and a radial thrust hearing at its upper end, avertically elongated shaft having two parallel bores each extendingsubstantially throughout its length, said shaft being supported by saidweight-sustaining bearing and receiving said stub shaft and said radialthrust bearing in one of its bores, a screen support over said shafthaving a downwardly projecting stub shaft and a weight-supporting rollerbearing around the upper end thereof, the lower end of said stub shaftbeing provided with a radial thrust bearing, said downwardly projectingstub shaft and its radial thrust bearing being received in the otherbore of said vertically elongated and the weighasupporting bearing ofsaid downwardly projecting stub shaft being supported by the upper endof said vertically elongated shaft, a pulley joined at its center tosaid vertically elongated shaft near the lower end of the latter, arelatively light weight secured to said pulley and disposed at the sideof the vertically elongated shaft adjacent said downwardly projectingstub shaft, whereby said relatively light weight and the scr: n mayexert centrifugal forces in the same direction, and a relatively heavyweight at the other side of said vertically elongated shaft and rigidlyjoined to the upper end thereof for exerting 2. correspondingcentrifugal force in the other direction; an upper bracket secured tosaid screen support, a lower bracket secured to one of said side bars ofthe base and projecting inwardly from the latter, a vertical shaftextending between said upper and lower brackets, and universal jointseonnecting the ends of said vertical shaft with said

